Class BranchPattern

docopt_private.h:140–216

	};

	class BranchPattern
	: public Pattern {
	public:
		BranchPattern(PatternList children = {})
		: fChildren(std::move(children))
		{}

		Pattern& fix() {
			UniquePatternSet patterns;
			fix_identities(patterns);
			fix_repeating_arguments();
			return *this;
		}

		virtual std::string const& name() const override {
			throw std::runtime_error("Logic error: name() shouldnt be called on a BranchPattern");
		}

		virtual value const& getValue() const {
			throw std::runtime_error("Logic error: name() shouldnt be called on a BranchPattern");
		}

		virtual std::vector<Pattern*> flat(bool (*filter)(Pattern const*)) override {
			if (filter(this)) {
				return {this};
			}

			std::vector<Pattern*> ret;
			for(auto& child : fChildren) {
				auto sublist = child->flat(filter);
				ret.insert(ret.end(), sublist.begin(), sublist.end());
			}
			return ret;
		}

		virtual void collect_leaves(std::vector<LeafPattern*>& lst) override final {
			for(auto& child : fChildren) {
				child->collect_leaves(lst);
			}
		}

		void setChildren(PatternList children) {
			fChildren = std::move(children);
		}

		PatternList const& children() const { return fChildren; }

		virtual void fix_identities(UniquePatternSet& patterns) {
			for(auto& child : fChildren) {
				// this will fix up all its children, if needed
				if (auto bp = dynamic_cast<BranchPattern*>(child.get())) {
					bp->fix_identities(patterns);
				}

				// then we try to add it to the list
				auto inserted = patterns.insert(child);
				if (!inserted.second) {
					// already there? then reuse the existing shared_ptr for that thing